Aestus
| Country of origin | Germany |
|---|---|
| First flight | 30 October 1997 |
| Last flight | 25 July 2018 |
| Designer | Ottobrunn Space Propulsion Centre |
| Manufacturer | Astrium |
| Application | Upper stage engine for the orbital insertion of heavy payloads |
| Associated LV | ESA |
| Successor | Aestus II |
| Status | Retired |
| Liquid-fuel engine | |
| Propellant | Nitrogen tetroxide (N2O4) / MMH |
| Mixture ratio | 1.9 |
| Cycle | Pressure-fed engine |
| Configuration | |
| Nozzle ratio | 84 |
| Performance | |
| Thrust, vacuum | 29.6 kN (6,654 lbf) |
| Chamber pressure | 11 bar |
| Specific impulse, vacuum | 324 s (3.18 km/s) |
| Burn time | 1100s |
| Dimensions | |
| Length | 2.20 m |
| Diameter | 1.31 m |
| Dry mass | 111 kg |
| Used in | |
| Ariane 5 G and ES Ariane 6.1 (proposed) | |
| References | |
| References | |
| Country of origin | Germany, United States |
|---|---|
| Designer | Ottobrunn Space Propulsion Centre, Pratt & Whitney Rocketdyne |
| Manufacturer | Astrium, Pratt & Whitney Rocketdyne |
| Application | Upper stage engine for the orbital insertion of heavy payloads |
| Associated LV | ESA |
| Predecessor | Aestus |
| Status | In development |
| Liquid-fuel engine | |
| Propellant | Nitrogen tetroxide (N2O4) / MMH |
| Mixture ratio | 1.9 |
| Cycle | Pump-fed engine |
| Pumps | XLR-132 |
| Configuration | |
| Nozzle ratio | 84 |
| Performance | |
| Thrust, vacuum | 55.4 kN (12,450 lbf) |
| Chamber pressure | 60 bar |
| Specific impulse, vacuum | 340 s (3.3 km/s) |
| Burn time | 600s |
| Dimensions | |
| Length | 2.29 m |
| Diameter | 1.31 m |
| Dry mass | 138 kg |
| References | |
| References | |
Aestus is a hypergolic liquid rocket engine used on an upper stage of Ariane 5 family rockets for the orbital insertion. It features unique design of 132 coaxial injection elements causing swirl mixing of the MMH propellants with nitrogen tetroxide oxidizer. The pressure-fed engine allows for multiple re-ignitions.